US2668162A - Preparation of high molecular weight polyhydroxyacetic ester - Google Patents
Preparation of high molecular weight polyhydroxyacetic ester Download PDFInfo
- Publication number
- US2668162A US2668162A US277726A US27772652A US2668162A US 2668162 A US2668162 A US 2668162A US 277726 A US277726 A US 277726A US 27772652 A US27772652 A US 27772652A US 2668162 A US2668162 A US 2668162A
- Authority
- US
- United States
- Prior art keywords
- glycolide
- antimony
- polymer
- polyhydroxyacetic
- molecular weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D319/00—Heterocyclic compounds containing six-membered rings having two oxygen atoms as the only ring hetero atoms
- C07D319/10—1,4-Dioxanes; Hydrogenated 1,4-dioxanes
- C07D319/12—1,4-Dioxanes; Hydrogenated 1,4-dioxanes not condensed with other rings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
- C08G63/06—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from hydroxycarboxylic acids
- C08G63/08—Lactones or lactides
Definitions
- This invention relates to the preparation of polymeric plastic materials and :more particularly to an improved processior -preparing high molecular weight polyhydroxyacetic ester.
- An object of the present invention is to produce by a simple and economical process, high molecular weight polyh-ydroxyacetic esters :capable of .being'm'elteextruded into strong'or-ientable fibers..tand. self supporting thinwfilm.
- An other object is to produce such .polyhydroxy acetic esters directly from glycolide.
- hydroxyacetic acid has been polymerized under tain conditions hereinalfter specified, 'be,.poly-.
- the present process comprises heating pure, dryglycOlideiin, an inertatmosphere, i. e., in an atmosphere of nitrogen, in the presence of a catalytic ,quantity of. an antimony compound from thelgroupconsisting of. antimony trioxidean'd antimony'trihali'des at a temperature between 150 C. andi'24'5 'Pref 1- erabl y, the reactionjispermittedto-proceed at a.
- antimony trifiuoride is the vprefen ed catalyst
- any antimony-.compnun'dxfrom the:group consisting of antimony .trioxi'dez and antimony trihalides, such .as antimony :tri'chl'oritle, anti mony .tribromiderand antimony tri-ti'oiiili'e :e'fieetively catalyzes the reaction.
- Catalyst-concentrations ranging .from 0:01???) ttoil';li%- 'mayr be employed, andv 0.03%, iba'sedfsupon the weight of glycolide or combined weiglitstof glycolide land lactide 101 other lacti'cles, ii's preferred.
- the'catalyst concentration-is decreasedibelow- 0.01% or increased -:a;bove.;0sls%' them'elt: viscosity of the 'resulting- -polym-eriis l'ower than that which may be obtained-ioperating withinithe specified range of catalyst concentration.
- the process of the present invention zmay be employed with advantage toprepare copolymers of glycolide withsmall quantities-e. g-., up' 'to 15%, of other lactidos such as "lactide and 'disalicylide.
- acopolymerof /10 -glycolideilactide offers two advantagesoverthe 'homopolymer-'of "g'lycolide;
- One advantage is thatthe melting"point-ofthe copolymer is lower than "the homopolymerf-b eing in the neighborhood of 200 6.
- glycolide The presence of water or acid impurities in glycolide tends to retard polymerization, and the resulting polyhydroxyacetic ester will not have a molecular weight suitable for extrusion into films or filaments.
- polymerization of impure glycolide usually results in the formation of a polymer having a melt viscosity less than 400 poises, while pure glycolide gives polymers having melt viscosities up to 50,000 poises.
- polyhydroxyacetic esters having melt viscosities substantially greater than 27,000 poises are extremely difiicult to extrude into films or filaments.
- Pure, dry (i. e., anhydrous) glycolide may conveniently be prepared in high yield by the depolymerization of low molecular weight polyhydroxyacetic ester which is formed as a by-product in various known processes of converting hydroxyacetic acid directly to high molecular weight polyhydroxyacetic ester.
- the following example typifies the preparation of glycolide by this method:
- Example A A charge of 4,000 parts of crude hydroxyacetic acid flake was heated at atmospheric pressure until the temperature of the liquid reached 175- 185 C. The temperature was maintained at this range for 2 hours or silghtly longer until water ceased to distill. The pressure was then reduced over a period of /2 hour to 150 mm. of mercury; and the temperature was maintained between 175-185 C. for 2 hours, or, again for a slightly longer time, until water ceased to distill. The product obtained was poured into an enamel pan and, after solidification, the white, brittle polymer was reduced to a free-flowing powder in a cutting machine.
- the apparatus for depolymerizing the above polyhydroxyacetic ester to form glycolide consisted of a three-necked reaction vessel equipped with a stainless steel stirrer, and provision for introducing the powdered polymer in increments through one neck and for take-on of the glycolide distillate through a downward connection tube wound with an electrical strip heater.
- a supply vessel containing the powdered polymer was attached by means of heavy-walled, flexible tubing to a stopcock so that the portion above the stopcock could be alternately filled and discharged into the reaction vessel.
- a steady stream of nitrogen was introduced through the polymer inlet tube to prevent accumulation or" glycolide distillate and consequent plugging.
- a receiver was cooled in an ice water bath and equipped with an air condenser to trap most of the uncondensed glycolide. Since the nitrogen stream tended to carry glycolide beyond the receiver, three traps Were interposed to protect the pump. One trap was a three-necked vessel filled with steel wool and immersed in an ice water bath, and the other two were standard Dry Ice-acetone tra s.
- the glycolide was purified by 2 or 3 recrystallizations from chemically pure ethyl acetate. In all cases, the crude glycolide was added to approximately twice its weight of ethyl acetate; solution was efiected at the boiling point; decolorizing charcoal was added; and reflux continued for hour. The solution was filtered while hot; cooled; and white glycolide crystals were obtained on filtering and drying. Further recrystallizations were conducted in a similar manner, but the decolorizing charcoal treatment was omitted.
- Example 1 Antimony trifiuoride (0.03% by weight of dry glycolide) was added to 2,300 parts of pure, dry glycolide in a closed reaction vessel. Nitrogen was allowed to pass over the surface of the material in the vessel. The reaction vessel was heated to C. by means of an oil bath and the contents stirred for one hour at that temperature. Stirring was stopped at this point since the material had become too viscous; and heating at 195 C. was maintained for one more hour, after which the temperature was quickly raised to 230 C. and maintained for hour. After solidification, the resulting polymer (M. P. 215-220 C.) was pulverized and further dried. The resulting polyhydroxyacetic ester had a melt viscosity of 20,000 poises at 245 C. and 6,900 poises at 255 C. The ground polymer was extruded into a tough, colddrawable, stretchable, and self-supporting film. The film had a melt viscosity of 1,800 poises at 245 C.
- the most characteristic single indication of plastic properties in high molecular weight polyhydroxyacetic esters is the ability of the polymer to form a highly viscous melt. Since the polymers degrade with increasing rapidity as the temperature is raised above the melting point, a standard temperature of 245 C. was selected for comparative tests. This is near the melting point but is sufficiently above it to avoid melting difiiculties. It has been found that at 245 C. a polyhydroxyacetic ester must have a melt viscosity, measured by the method of Flory (Journal of the American Chemical Society, 62, 1057 (1940) of at least 400 poises before it can be molded into useful shaped articles, the preferred viscosity range being from 1,000 to 10,000 poises for extrusion into fibers and films.
- the polymer melt is too fluid and non-adherent to handle properly during forming operations; and the shaped products are increasingly brittle, non-cohesive and weak.
- the melt viscosity can be so high that the polymer is difficult to mold or extrude.
- Example 2 Antimony trichloride (approximately 0.10% by 1
- Example 3 Antimony trioxide (0.03% by weight of dry glycolide) was added to 20.0 parts of pure, dry glycolide in a tubular reaction vessel (diameter 0.5") provided with a side-arm near the top of the tube. Nitrogen was allowed to pass over the surface of the material in the tube end out through the side-arm. The tube was heated to 155 C. by means of a vapor bath and maintained at that temperature for 2 hours. Then the temperature was raised to 241 C. in an appropriate vapor bath. After 1.8 hours at 241 C., a polymer was produced having a melt viscosity of 4,300 poises at 241 0.
- Example 4 Antimony trifiuoride (0.03% based upon the combined weight of glycolide and lactide) was added to 4.5 parts of pure, dry glycolide and 0.5 part of pure, dry lactide in a reaction vessel. Nitrogen was allowed to pass over the surface of the material in the vessel. The reaction vessel was heated to 195-200 C. by means of an oil bath and maintained at that temperature for 2% hours. Stirring of the reaction mixture was stopped after one hour because the material became too viscous. The resulting polymer was allowed to cool, and the solidified material was pulverized to a powder. After further drying, the
- polymer (M. P. ZOO-205 C.) had a meltviscosity of 15,000 poises at 218 C. and a melt viscosity of 7,000 poises at 245 C.
- the polymer was extruded into a tough, clear, cold-drawable, stretchable and self-supporting film at 210 C.
- the resulting film had a melt viscosity of 1,300 poises at 218 C.
- a particular advantage of the present invention is that it provides a process of forming high molecular weight polyhydroxyacetic esters by polymerizing a by-product of known processes for preparing the polymeric ester, glycolide.
- a process for preparing polyhydroxyacetic esters which comprises polymerizing glycolide by heating glycolide, free of Water and acid impurities, at a temperature of from about C. to about 245 C. in the presence of a catalytic amount of an antimony compound from the group consisting of antimony trioxide and antimony trihalides.
- a process for preparing polyhydroxyacetic esters which comprises heating glycolide, free of water and acid impurities, at a temperature of from about 150 C. to about 245 C. in the presence of from 0.01% to 1.0% by weight, based on the weight of glycolide, of an antimony compound from the group consisting of antimony trioxide and antimony trihalides.
- a process for preparing polyhydroxyacetic ester homopolymer which comprises polymerizing lycolide by initially heating glycolide, free of water and acid impurities, in an atmosphere of inert gas, at a temperature of from 150 C. to 200 0., to form a low molecular weight polymer, and thereafter heating the polymer at a temperature of from 220 C. to 245 C. until a polymer having a melt viscosity at 245 C. of at least 400 poises is obtained, the entire reaction being carried outin the presence of from 0.01% to 1.0% by weight, based on the weight of glycolide, of an antimony compound from the group consisting of antimony trioxide and antimony trihalides as catalyst.
Description
Iatented Feb. 2, 1954 UNITED was PATENT oil-"rice:
- 'B P RA :QN:"Q GH. MOLECULAR IGgHT. LESTER .BOLYHYDROXYACETIC.
TNo rawi g, Application Marshal), 1,952,,
This invention relates to the preparation of polymeric plastic materials and :more particularly to an improved processior -preparing high molecular weight polyhydroxyacetic ester.
An object of the present invention is to produce by a simple and economical process, high molecular weight polyh-ydroxyacetic esters :capable of .being'm'elteextruded into strong'or-ientable fibers..tand. self supporting thinwfilm. An other object is to produce such .polyhydroxy acetic esters directly from glycolide. These and other objects will more clearly appear hereinafter.
In processes heretofore employed for the prep,- aration of high molecular weight polyhydroxyacetic esters of the general formula:
hydroxyacetic acid has been polymerized under tain conditions hereinalfter specified, 'be,.poly-.
merized to, produce fiber- .andfilm-Jforming polyhydroxyaceticiesters such as .are ,producediby thebefore-mentioned polymerization of 'hydrox-yacetic acid.
The present invention, 'therefOreQbrieflystated,
ompris s h at n p r lycolide in the presence of a catalytic amount of an antimonycompound from the group consisting of antimbnytrioxi'de and antimony 'trihalides.
"More specifically, the present process comprises heating pure, dryglycOlideiin, an inertatmosphere, i. e., in an atmosphere of nitrogen, in the presence of a catalytic ,quantity of. an antimony compound from thelgroupconsisting of. antimony trioxidean'd antimony'trihali'des at a temperature between 150 C. andi'24'5 'Pref 1- erabl y, the reactionjispermittedto-proceed at a.
temperaturebelow the meltingflpoint of thepolyhydroxyacetic' ester in order to,initiate,polymer-. ization, while minimizing darkening of the molten mass, foraperiod just s'horto fthejtime atwhich solidification "of the polymer produced com memos and thereafter the temperature is raised above the melting point to prevent solidification of the'po'lymer to "complete polymer zat on, n to permitmelt extrusion. Usuallminthepreparationof the polyhydroxyacetic-ester -from glycolide, the initial portion of the reaction is carried out at a tempQra-tureefirom 150 C.-200 C. and thereafter the temperature is raised to 220 -C.-.245
The melting point. ofthe-:polyhydroxyacetic; ester is-in the, nBighbIOIhOQdi'iOf; 21:5. 220f 16; Consequently, .in the preferred procedure, the initial portion of theireaction;iszcaazriedsoutz-ata, temperaturenf from-150910;. :to 290 3 "anrlarthe latter portion :of the .reaotionzissca-rried with-1: in the range 220=G-. -.-.2452. ,lfsuailwappreeiable degradation of the polymeritakes.:placeabove 245 C.; and itis preierredtto carry outthed'at-r terportion of the :reaction-ratiartemperaturesonlyslightly, i. e., 5-10 .0.,aboveathemeltingrpointiof the polymer. This isforEthezpurposenfiavoiding excessive exposure of the. polymer-:tozelevated temperatures,v :i. e.,; above 'thezmelting: point.
While antimony trifiuoride is the vprefen ed catalyst, any antimony-.compnun'dxfrom the:group, consisting of antimony .trioxi'dez and antimony trihalides, such .as antimony :tri'chl'oritle, anti mony .tribromiderand antimony tri-ti'oiiili'e :e'fieetively catalyzes the reaction. Catalyst-concentrations ranging .from 0:01???) ttoil';li%- ='mayr be employed, andv 0.03%, iba'sedfsupon the weight of glycolide or combined weiglitstof glycolide land lactide 101 other lacti'cles, ii's preferred. Usually; when the'catalyst concentration-is decreasedibelow- 0.01% or increased -:a;bove.;0sls%', them'elt: viscosity of the 'resulting- -polym-eriis l'ower than that which may be obtained-ioperating withinithe specified range of catalyst concentration.
The process of the present invention zmay be employed with advantage toprepare copolymers of glycolide withsmall quantities-e. g-., up' 'to 15%, of other lactidos such as "lactide and 'disalicylide. For example,- the preparation of acopolymerof /10 -glycolideilactide"offers two advantagesoverthe 'homopolymer-'of "g'lycolide; One advantage is thatthe melting"point-ofthe copolymer is lower than "the homopolymerf-b eing in the neighborhood of 200 6. and the entire reaction can be conducted alt-approximately -the melting point ofthecopolymer; Operation-'afith e lower temperaturesdecreases thera'teoi? degradation of the polymer which "gives aipoiymer'oi, lighter color. Another advantage thatjthe copolymer can:.be successiully 'quenched vhenibeing extruded into film because ithecopolymer fis; less cryst lline. 1 Oni'the "other. hand; hefhomap yme ho 'ajs ater tendency torrystalli e.
on "extrusionrandthfereby tendsjtojform'fopaque.
areas in the film.
The presence of water or acid impurities in glycolide tends to retard polymerization, and the resulting polyhydroxyacetic ester will not have a molecular weight suitable for extrusion into films or filaments. For example, polymerization of impure glycolide usually results in the formation of a polymer having a melt viscosity less than 400 poises, while pure glycolide gives polymers having melt viscosities up to 50,000 poises. However, polyhydroxyacetic esters having melt viscosities substantially greater than 27,000 poises are extremely difiicult to extrude into films or filaments.
Pure, dry (i. e., anhydrous) glycolide may conveniently be prepared in high yield by the depolymerization of low molecular weight polyhydroxyacetic ester which is formed as a by-product in various known processes of converting hydroxyacetic acid directly to high molecular weight polyhydroxyacetic ester. The following example typifies the preparation of glycolide by this method:
Example A A charge of 4,000 parts of crude hydroxyacetic acid flake was heated at atmospheric pressure until the temperature of the liquid reached 175- 185 C. The temperature was maintained at this range for 2 hours or silghtly longer until water ceased to distill. The pressure was then reduced over a period of /2 hour to 150 mm. of mercury; and the temperature was maintained between 175-185 C. for 2 hours, or, again for a slightly longer time, until water ceased to distill. The product obtained was poured into an enamel pan and, after solidification, the white, brittle polymer was reduced to a free-flowing powder in a cutting machine. 2,972 parts of polyhydroxyacetic ester (low molecular weight material having a melt viscosity of less than 50 poises) were obtained (97.4% of the theoretical amount) while the water collected amounted to 932 parts (98.2% of the theoretical amount). The 9'7 parts unaccounted for (2.4%) were lost on transfer.
The apparatus for depolymerizing the above polyhydroxyacetic ester to form glycolide consisted of a three-necked reaction vessel equipped with a stainless steel stirrer, and provision for introducing the powdered polymer in increments through one neck and for take-on of the glycolide distillate through a downward connection tube wound with an electrical strip heater. A supply vessel containing the powdered polymer was attached by means of heavy-walled, flexible tubing to a stopcock so that the portion above the stopcock could be alternately filled and discharged into the reaction vessel. A steady stream of nitrogen was introduced through the polymer inlet tube to prevent accumulation or" glycolide distillate and consequent plugging. A receiver was cooled in an ice water bath and equipped with an air condenser to trap most of the uncondensed glycolide. Since the nitrogen stream tended to carry glycolide beyond the receiver, three traps Were interposed to protect the pump. One trap was a three-necked vessel filled with steel wool and immersed in an ice water bath, and the other two were standard Dry Ice-acetone tra s.
1 000 parts of powdered, low molecular weight polymer produced as previously described were thoroughly mixed with 10 parts of antimony trioxide and placed in the supply vessel. The polymer was introduced from the supp y vessel into the reaction vessel maintained at 270-285 C. at
4 the rate of 200 parts per hour in five-part increments with the pressure of the system maintained at 12-15 mm. of mercury. A 93% yield of crude glycolide distillate was collected as a white to light yellow solid in the receiver.
Polymerization of the crude glycolide as obtained according to the above process showed that it was necessary to purify the crude glycolide in order to obtain high yields of high molecular weight polyhydroxyacetic ester. The glycolide was purified by 2 or 3 recrystallizations from chemically pure ethyl acetate. In all cases, the crude glycolide was added to approximately twice its weight of ethyl acetate; solution was efiected at the boiling point; decolorizing charcoal was added; and reflux continued for hour. The solution was filtered while hot; cooled; and white glycolide crystals were obtained on filtering and drying. Further recrystallizations were conducted in a similar manner, but the decolorizing charcoal treatment was omitted.
The following examples of preferred embodiments will further serve to illustrate the principles and practice of the process of the present invention. Parts and percentages are by weight unless otherwise indicated:
In each of the following examples, pure glycolide, free from traces of water and acid impurities and having a melting point between 83.8-84.3" 0., was employed.
Example 1 Antimony trifiuoride (0.03% by weight of dry glycolide) was added to 2,300 parts of pure, dry glycolide in a closed reaction vessel. Nitrogen was allowed to pass over the surface of the material in the vessel. The reaction vessel was heated to C. by means of an oil bath and the contents stirred for one hour at that temperature. Stirring was stopped at this point since the material had become too viscous; and heating at 195 C. was maintained for one more hour, after which the temperature was quickly raised to 230 C. and maintained for hour. After solidification, the resulting polymer (M. P. 215-220 C.) was pulverized and further dried. The resulting polyhydroxyacetic ester had a melt viscosity of 20,000 poises at 245 C. and 6,900 poises at 255 C. The ground polymer was extruded into a tough, colddrawable, stretchable, and self-supporting film. The film had a melt viscosity of 1,800 poises at 245 C.
The most characteristic single indication of plastic properties in high molecular weight polyhydroxyacetic esters is the ability of the polymer to form a highly viscous melt. Since the polymers degrade with increasing rapidity as the temperature is raised above the melting point, a standard temperature of 245 C. was selected for comparative tests. This is near the melting point but is sufficiently above it to avoid melting difiiculties. It has been found that at 245 C. a polyhydroxyacetic ester must have a melt viscosity, measured by the method of Flory (Journal of the American Chemical Society, 62, 1057 (1940) of at least 400 poises before it can be molded into useful shaped articles, the preferred viscosity range being from 1,000 to 10,000 poises for extrusion into fibers and films. Below this limit, the polymer melt is too fluid and non-adherent to handle properly during forming operations; and the shaped products are increasingly brittle, non-cohesive and weak. On the other hand, the melt viscosity can be so high that the polymer is difficult to mold or extrude.
Example 2 Antimony trichloride (approximately 0.10% by 1 Example 3 Antimony trioxide (0.03% by weight of dry glycolide) was added to 20.0 parts of pure, dry glycolide in a tubular reaction vessel (diameter 0.5") provided with a side-arm near the top of the tube. Nitrogen was allowed to pass over the surface of the material in the tube end out through the side-arm. The tube was heated to 155 C. by means of a vapor bath and maintained at that temperature for 2 hours. Then the temperature was raised to 241 C. in an appropriate vapor bath. After 1.8 hours at 241 C., a polymer was produced having a melt viscosity of 4,300 poises at 241 0.
Example 4 Antimony trifiuoride (0.03% based upon the combined weight of glycolide and lactide) was added to 4.5 parts of pure, dry glycolide and 0.5 part of pure, dry lactide in a reaction vessel. Nitrogen was allowed to pass over the surface of the material in the vessel. The reaction vessel was heated to 195-200 C. by means of an oil bath and maintained at that temperature for 2% hours. Stirring of the reaction mixture was stopped after one hour because the material became too viscous. The resulting polymer was allowed to cool, and the solidified material was pulverized to a powder. After further drying, the
polymer (M. P. ZOO-205 C.) had a meltviscosity of 15,000 poises at 218 C. and a melt viscosity of 7,000 poises at 245 C. The polymer was extruded into a tough, clear, cold-drawable, stretchable and self-supporting film at 210 C. The resulting film had a melt viscosity of 1,300 poises at 218 C.
A particular advantage of the present invention is that it provides a process of forming high molecular weight polyhydroxyacetic esters by polymerizing a by-product of known processes for preparing the polymeric ester, glycolide. A
made without departing from the'spirit and scope of my invention, it is to be understood that said invention is in no way restricted save as set forth in the following claims.
I claim:
1. A process for preparing polyhydroxyacetic esters which comprises polymerizing glycolide by heating glycolide, free of Water and acid impurities, at a temperature of from about C. to about 245 C. in the presence of a catalytic amount of an antimony compound from the group consisting of antimony trioxide and antimony trihalides.
2. A process for preparing polyhydroxyacetic esters which comprises heating glycolide, free of water and acid impurities, at a temperature of from about 150 C. to about 245 C. in the presence of from 0.01% to 1.0% by weight, based on the weight of glycolide, of an antimony compound from the group consisting of antimony trioxide and antimony trihalides.
3. The process of claim 2 wherein the polymerization is carried out in an inert atmosphere.
4. The process of claim 2 wherein 0.03% by weight of antimony compound is used.
5. The process of claim 2 wherein the antimony compound is antimony trifiuoride.
6. A process for preparing polyhydroxyacetic ester homopolymer which comprises polymerizing lycolide by initially heating glycolide, free of water and acid impurities, in an atmosphere of inert gas, at a temperature of from 150 C. to 200 0., to form a low molecular weight polymer, and thereafter heating the polymer at a temperature of from 220 C. to 245 C. until a polymer having a melt viscosity at 245 C. of at least 400 poises is obtained, the entire reaction being carried outin the presence of from 0.01% to 1.0% by weight, based on the weight of glycolide, of an antimony compound from the group consisting of antimony trioxide and antimony trihalides as catalyst.
7. The process of claim 6 wherein the polymerization reaction is carried out in an atmosphere of nitrogen gas and in the presence of about 0.03% by weight, based on the weight of glycolide, or antimony trifluoride.
CHARLES E. LOWE.
References Cited in the file of this patent UNITED STATES PATENTS Number
Claims (1)
1. A PROCESS FOR PREPARING POLYHYDROXYACETIC ESTERS WHICH COMPRISES POLYMERIZING GLYCOLIDE BY HEATING GLYCOLIDE, FREE OF WATER AND ACID IMPURITIES, AT A TEMPERATURE OF FROM ABOUT 150* C. TO ABOUT 245* C. IN THE PRESENCE OF A CATALYTIC AMOUNT OF AN ANTIMONY COMPOUND FROM THE GROUP CONSISTING OF ANTIMONY TRIOXIDE AND ANTIMONY TRIHALIDES.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US277726A US2668162A (en) | 1952-03-20 | 1952-03-20 | Preparation of high molecular weight polyhydroxyacetic ester |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US277726A US2668162A (en) | 1952-03-20 | 1952-03-20 | Preparation of high molecular weight polyhydroxyacetic ester |
Publications (1)
Publication Number | Publication Date |
---|---|
US2668162A true US2668162A (en) | 1954-02-02 |
Family
ID=23062108
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US277726A Expired - Lifetime US2668162A (en) | 1952-03-20 | 1952-03-20 | Preparation of high molecular weight polyhydroxyacetic ester |
Country Status (1)
Country | Link |
---|---|
US (1) | US2668162A (en) |
Cited By (114)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3435008A (en) * | 1967-08-22 | 1969-03-25 | American Cyanamid Co | Method for preparation of isomerically pure beta-glycolide and polymerization method for glycolide compositions employing partial hydrolyzate of said beta-glycolide |
US3440225A (en) * | 1963-03-23 | 1969-04-22 | Wolfen Filmfab Veb | Process for the manufacture of shaped structures from polyglycolides |
US3442871A (en) * | 1966-05-04 | 1969-05-06 | American Cyanamid Co | Process for polymerizing a glycolide |
US3457280A (en) * | 1967-06-12 | 1969-07-22 | American Cyanamid Co | Alpha-glycolide and methods for the isolation thereof |
US3468853A (en) * | 1966-06-15 | 1969-09-23 | American Cyanamid Co | Process of polymerizing a glycolide |
US3636956A (en) * | 1970-05-13 | 1972-01-25 | Ethicon Inc | Polylactide sutures |
US3797499A (en) * | 1970-05-13 | 1974-03-19 | Ethicon Inc | Polylactide fabric graphs for surgical implantation |
US3846382A (en) * | 1971-02-25 | 1974-11-05 | American Cyanamid Co | Sterile medical dusting powder |
US3982543A (en) * | 1973-04-24 | 1976-09-28 | American Cyanamid Company | Reducing capillarity of polyglycolic acid sutures |
US4048256A (en) * | 1976-06-01 | 1977-09-13 | American Cyanamid Company | Normally-solid, bioabsorbable, hydrolyzable, polymeric reaction product |
US4095600A (en) * | 1976-06-01 | 1978-06-20 | American Cyanamid Company | Normally-solid, bioabsorbable, hydrolyzable, polymeric reaction product |
US4243775A (en) * | 1978-11-13 | 1981-01-06 | American Cyanamid Company | Synthetic polyester surgical articles |
US4377010A (en) * | 1978-11-08 | 1983-03-22 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Biocompatible material comprising a base polymer bulk graft polymerized with an ethylenically unsaturated carboxylic acid |
US4443430A (en) * | 1982-11-16 | 1984-04-17 | Ethicon, Inc. | Synthetic absorbable hemostatic agent |
DE3433331A1 (en) * | 1983-09-20 | 1985-03-28 | Materials Consultants Oy, Tampere | SURGICAL DEVICE FOR IMMOBILIZING BONE FRACTURES |
US4523591A (en) * | 1982-10-22 | 1985-06-18 | Kaplan Donald S | Polymers for injection molding of absorbable surgical devices |
US4594407A (en) * | 1983-09-20 | 1986-06-10 | Allied Corporation | Prosthetic devices derived from krebs-cycle dicarboxylic acids and diols |
US4727163A (en) * | 1985-07-11 | 1988-02-23 | E. I. Du Pont De Nemours And Company | Process for preparing highly pure cyclic esters |
US4744365A (en) * | 1986-07-17 | 1988-05-17 | United States Surgical Corporation | Two-phase compositions for absorbable surgical devices |
US4835293A (en) * | 1987-02-24 | 1989-05-30 | E. I. Du Pont De Nemours And Company | Atmospheric pressure process for preparing pure cyclic esters |
US4886870A (en) * | 1984-05-21 | 1989-12-12 | Massachusetts Institute Of Technology | Bioerodible articles useful as implants and prostheses having predictable degradation rates |
US4891225A (en) * | 1984-05-21 | 1990-01-02 | Massachusetts Institute Of Technology | Bioerodible polyanhydrides for controlled drug delivery |
US4906474A (en) * | 1983-03-22 | 1990-03-06 | Massachusetts Institute Of Technology | Bioerodible polyanhydrides for controlled drug delivery |
US4946929A (en) * | 1983-03-22 | 1990-08-07 | Massachusetts Institute Of Technology | Bioerodible articles useful as implants and prostheses having predictable degradation rates |
EP0450777A2 (en) * | 1990-04-06 | 1991-10-09 | Director-General Of The Agency Of Industrial Science And Technology | Biodegradable plastics composition |
US5061281A (en) * | 1985-12-17 | 1991-10-29 | Allied-Signal Inc. | Bioresorbable polymers and implantation devices thereof |
US5076983A (en) * | 1990-07-16 | 1991-12-31 | E. I. Du Pont De Nemours And Company | Polyhydroxy acid films |
WO1992000292A1 (en) * | 1990-06-28 | 1992-01-09 | E.I. Du Pont De Nemours And Company | Continuous catalyzed vapor phase dimeric cyclic ester process |
WO1992000974A1 (en) * | 1990-07-13 | 1992-01-23 | E.I. Du Pont De Nemours And Company | High yield recycle process for lactide |
US5089632A (en) * | 1991-01-30 | 1992-02-18 | E. I. Du Pont De Nemours And Company | Process for preparing cyclic esters using a fluorocarbon |
US5091544A (en) * | 1990-05-08 | 1992-02-25 | E. I. Du Pont De Nemours And Company | Process for rapid conversion of oligomers to cyclic esters |
WO1992006969A1 (en) * | 1990-10-23 | 1992-04-30 | E.I. Du Pont De Nemours And Company | Solvent scrubbing recovery of cyclic esters |
US5124103A (en) * | 1984-03-06 | 1992-06-23 | United States Surgical Corporation | Two phase compositions for absorbable surgical devices |
US5236560A (en) * | 1992-03-13 | 1993-08-17 | E. I. Du Pont De Nemours And Company | Solventless dimeric cyclic ester distillation process |
US5266706A (en) * | 1990-10-23 | 1993-11-30 | E. I. Du Pont De Nemours & Company | Solvent scrubbing recovery of lactide and other dimeric cyclic esters |
US5274127A (en) * | 1990-09-18 | 1993-12-28 | Biopak Technology, Ltd. | Lactide production from dehydration of aqueous lactic acid feed |
US5288881A (en) * | 1992-03-12 | 1994-02-22 | E. I. Du Pont De Nemours And Company | Continuous reduced pressure dimeric cyclic ester production |
US5319107A (en) * | 1990-09-18 | 1994-06-07 | Biopak Technology, Ltd. | Method to produce cyclic esters |
US5332839A (en) * | 1990-09-18 | 1994-07-26 | Biopak Technology, Ltd. | Catalytic production of lactide directly from lactic acid |
US5342969A (en) * | 1993-03-03 | 1994-08-30 | E. I. Du Pont De Nemours And Company | Recovery of hydroxycarboxylic acid values from poly(hydroxycarboxylic acids) |
EP0617029A1 (en) | 1993-03-25 | 1994-09-28 | United States Surgical Corporation | Purification of 1,4-dioxan-2-one by crystallization |
US5399353A (en) * | 1986-06-20 | 1995-03-21 | Henkel Kommanditgesellschaft Auf Aktien | Preparations for covering undamaged and/or damaged areas of human or animal skin |
US5399665A (en) * | 1992-11-05 | 1995-03-21 | Massachusetts Institute Of Technology | Biodegradable polymers for cell transplantation |
US5403347A (en) * | 1993-05-27 | 1995-04-04 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US5420304A (en) * | 1992-03-19 | 1995-05-30 | Biopak Technology, Ltd. | Method to produce cyclic esters |
US5431679A (en) * | 1994-03-10 | 1995-07-11 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US5475063A (en) * | 1991-02-12 | 1995-12-12 | United States Surgical Corporation | Blends of glycolide and/or lactide polymers and caprolactone and/or trimethylene carbonate polymers and absorbable surgical devices made |
EP0701823A2 (en) | 1994-09-16 | 1996-03-20 | United States Surgical Corporation | Absorbable polymer and surgical articles fabricated therefrom |
US5522841A (en) * | 1993-05-27 | 1996-06-04 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US5545409A (en) * | 1989-02-22 | 1996-08-13 | Massachusetts Institute Of Technology | Delivery system for controlled release of bioactive factors |
US5618313A (en) * | 1994-10-11 | 1997-04-08 | United States Surgical Corporation | Absorbable polymer and surgical articles fabricated therefrom |
US5639466A (en) * | 1994-02-24 | 1997-06-17 | Chronopol, Inc. | Method for packaging foodstuffs |
US5675021A (en) * | 1992-03-19 | 1997-10-07 | Chronopol, Inc. | Method to produce and purify cyclic esters |
EP0805176A1 (en) * | 1996-04-30 | 1997-11-05 | Kureha Kagaku Kogyo Kabushiki Kaisha | Polyglycolic acid sheet and production process thereof |
EP0805175A1 (en) * | 1996-04-30 | 1997-11-05 | Kureha Kagaku Kogyo Kabushiki Kaisha | Oriented polyglycolic acid film and production process thereof |
US5686630A (en) * | 1993-09-29 | 1997-11-11 | Chronopol, Inc. | Purifying cyclic esters by aqueous solvent extraction |
US5756651A (en) * | 1996-07-17 | 1998-05-26 | Chronopol, Inc. | Impact modified polylactide |
US5830991A (en) * | 1996-02-09 | 1998-11-03 | Kureha Kagaku Kagyo Kk | Preparation process and purification process of dimeric cyclic ester of hydroxycarboxylic acid |
US5900491A (en) * | 1996-10-04 | 1999-05-04 | Mitsubishi Gas Chemical Co., Inc. | Preparation process and purification process of cyclic ester |
US5997568A (en) * | 1996-01-19 | 1999-12-07 | United States Surgical Corporation | Absorbable polymer blends and surgical articles fabricated therefrom |
US6007565A (en) * | 1997-09-05 | 1999-12-28 | United States Surgical | Absorbable block copolymers and surgical articles fabricated therefrom |
US6083524A (en) * | 1996-09-23 | 2000-07-04 | Focal, Inc. | Polymerizable biodegradable polymers including carbonate or dioxanone linkages |
WO2000064538A1 (en) | 1999-04-28 | 2000-11-02 | Medi Physics, Inc. | Products and methods for brachytherapy |
US6191236B1 (en) | 1996-10-11 | 2001-02-20 | United States Surgical Corporation | Bioabsorbable suture and method of its manufacture |
US6206908B1 (en) | 1994-09-16 | 2001-03-27 | United States Surgical Corporation | Absorbable polymer and surgical articles fabricated therefrom |
US6228954B1 (en) | 1991-02-12 | 2001-05-08 | United States Surgical Corporation | Blends of glycolide and/or lactide polymers and caprolactone and/or trimethylene carbonate polymers and absorabable surgical devices made therefrom |
US20010012847A1 (en) * | 1996-11-12 | 2001-08-09 | Lam Andrew C. | Methods and devices for providing prolonged drug therapy |
US6277927B1 (en) | 1997-11-26 | 2001-08-21 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
EP1133240A1 (en) * | 1998-10-02 | 2001-09-19 | Wm. Wrigley Jr. Company | Biodegradable chewing gum bases including plasticized poly(d,l-lactic acid) and copolymers thereof |
US6310218B1 (en) | 1993-02-17 | 2001-10-30 | E.I. Du Pont De Nemours And Company | Melt crystallization purification of lactides |
US6323307B1 (en) | 1988-08-08 | 2001-11-27 | Cargill Dow Polymers, Llc | Degradation control of environmentally degradable disposable materials |
US6387363B1 (en) | 1992-12-31 | 2002-05-14 | United States Surgical Corporation | Biocompatible medical devices |
WO2003006525A1 (en) * | 2001-07-10 | 2003-01-23 | Kureha Chemical Industry Company, Limited | Polyhydroxycarboxylic acid and its production process |
US6546188B1 (en) | 1998-01-16 | 2003-04-08 | Sony Corporation | Editing system and editing method |
US20030191326A1 (en) * | 2000-08-11 | 2003-10-09 | Kazuyuki Yamane | Process for the preparation of cyclic esters and method for purification of the same |
US20040015037A1 (en) * | 2000-11-01 | 2004-01-22 | Michael Rapach | Radioactive member and method of making |
US20040058164A1 (en) * | 1994-07-22 | 2004-03-25 | Bennett Steven L. | Bioabsorbable branched polymers containing units derived from dioxanone and medical/surgical devices manufactured therefrom |
US6716932B2 (en) | 2000-08-16 | 2004-04-06 | Tyco Healthcare Group Lp | High consistency absorbable polymeric resin |
US20040087805A1 (en) * | 2001-03-06 | 2004-05-06 | Kazuyuki Yamane | Glycolide production process, and glycolic acid composition |
US20040122240A1 (en) * | 2001-04-12 | 2004-06-24 | Kazuyuki Yamane | Glycolide production process, and glycolic acid oligomer for glycolide production |
US20040162580A1 (en) * | 2000-08-17 | 2004-08-19 | Matthew Hain | Sutures and coatings made from therapeutic absorbable glass |
EP1449864A1 (en) * | 2001-10-31 | 2004-08-25 | Kureha Chemical Industry Co., Ltd. | CRYSTALLINE POLYGLYCOLIC ACID, POLYGLYCOLIC ACID COMPOSITION AND PROCESSES FOR PRODUCTION OF BOTH |
US20040230026A1 (en) * | 2001-07-10 | 2004-11-18 | Kazuyuki Yamane | Polyester production process and reactor apparatus |
US20050208132A1 (en) * | 2002-07-29 | 2005-09-22 | Gayatri Sathyan | Methods and dosage forms for reducing side effects of benzisozazole derivatives |
US20050232995A1 (en) * | 2002-07-29 | 2005-10-20 | Yam Nyomi V | Methods and dosage forms for controlled delivery of paliperidone and risperidone |
US20060004183A1 (en) * | 2002-10-08 | 2006-01-05 | Hiroyuki Sato | Process for producing aliphatic polyester |
US20060235365A1 (en) * | 2001-11-02 | 2006-10-19 | World Wide Medical Technologies, Llc | Delivery system and method for interstitial radiation therapy using strands constructed with extruded strand housings |
US20070021642A1 (en) * | 2005-07-22 | 2007-01-25 | Worldwide Medical Technologies Llc | Devices to resist migration and rotation of implants used in brachytherapy and other radiation therapy |
WO2007086563A1 (en) | 2006-01-30 | 2007-08-02 | Kureha Corporation | Process for producing aliphatic polyester |
US20070265488A1 (en) * | 2006-05-09 | 2007-11-15 | Worldwide Medical Technologies Llc | After-loader for positioning implants for needle delivery in brachytherapy and other radiation therapy |
US7322928B2 (en) | 2003-03-17 | 2008-01-29 | Medi-Physics, Inc. | Products and methods for brachytherapy |
EP2036582A1 (en) | 1994-07-22 | 2009-03-18 | United States Surgical Corporation | Biobsorbable branched polymers containing units derived from dioxanone and medical/surgical devices manufactured therefrom |
US20090216063A1 (en) * | 2008-01-29 | 2009-08-27 | Biocompatibles Uk Limited | Bio-absorbable brachytherapy strands |
US20100015185A1 (en) * | 2007-03-01 | 2010-01-21 | Bioneedle Technologies Group B.V. | Biodegradable material based on opened starch |
US20100080839A1 (en) * | 2007-03-01 | 2010-04-01 | Bioneedle Technologies Group B.V. | Parenteral formulation |
EP2221333A1 (en) | 2004-03-18 | 2010-08-25 | Kureha Corporation | Process for producing aliphatic polyester reduced in residual cyclic ester content |
US20100261946A1 (en) * | 2000-11-16 | 2010-10-14 | Microspherix Llc | Flexible and/or elastic brachytherapy seed or strand |
WO2011007092A1 (en) | 2009-07-17 | 2011-01-20 | Arkema France | Polyhydroalkanoate composition exhibiting improved impact resistance |
US7874976B1 (en) | 2006-09-07 | 2011-01-25 | Biocompatibles Uk Limited | Echogenic strands and spacers therein |
US7874974B2 (en) | 2001-11-02 | 2011-01-25 | Biocompatibles Uk Limited | Delivery system and method for interstitial radiation therapy |
US7878964B1 (en) | 2006-09-07 | 2011-02-01 | Biocompatibles Uk Limited | Echogenic spacers and strands |
WO2011017153A1 (en) | 2009-07-28 | 2011-02-10 | E. I. Du Pont De Nemours And Company | Poly(hydroxyalkanoic acid) blown film |
EP2407463A1 (en) | 2010-07-14 | 2012-01-18 | Solvay SA | Process for the manufacture of a cyclic diester of an apha-hydroxyacid |
US8187159B2 (en) | 2005-07-22 | 2012-05-29 | Biocompatibles, UK | Therapeutic member including a rail used in brachytherapy and other radiation therapy |
US8399686B2 (en) | 2009-12-21 | 2013-03-19 | Evonik Degussa Corporation | Process for preparing cyclic esters comprising unsaturated functional groups and polyesters prepared from same |
WO2013063310A1 (en) | 2011-10-26 | 2013-05-02 | E. I. Du Pont De Nemours And Company | Multilayer film structure comprising renewably sourced materials |
US8729156B2 (en) | 2009-07-17 | 2014-05-20 | Arkema France | Polyhydroxyalkanoate composition exhibiting improved impact resistance at low levels of impact modifier |
EP2732832A2 (en) | 2012-11-14 | 2014-05-21 | Universitair Medisch Centrum Groningen (UMCG) | Drug delivery device comprising an active compound and a thermo-sensitive polymeric material |
WO2014080876A1 (en) | 2012-11-22 | 2014-05-30 | 株式会社クレハ | Method for producing glycolide, which is provided with rectification step by means of gas-liquid countercurrent contact, and method for purifying crude glycolide |
WO2014156809A1 (en) | 2013-03-27 | 2014-10-02 | 株式会社クレハ | Method for producing glycolide |
US9080013B2 (en) | 2013-07-22 | 2015-07-14 | Kureha Corporation | Production method for aliphatic polyester |
US10759097B2 (en) | 2017-01-27 | 2020-09-01 | Kureha Corporation | Molded article and use of same |
US11046665B2 (en) | 2017-01-24 | 2021-06-29 | Kureha Corporation | Method for producing α-hydroxycarboxylic acid dimeric cyclic ester |
CN116284698A (en) * | 2023-02-21 | 2023-06-23 | 内蒙古久泰新材料科技股份有限公司 | Production process for simultaneously preparing various molecular weight gradient degradable materials |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2585427A (en) * | 1951-01-11 | 1952-02-12 | Process fob preparing condensation |
-
1952
- 1952-03-20 US US277726A patent/US2668162A/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2585427A (en) * | 1951-01-11 | 1952-02-12 | Process fob preparing condensation |
Cited By (195)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3440225A (en) * | 1963-03-23 | 1969-04-22 | Wolfen Filmfab Veb | Process for the manufacture of shaped structures from polyglycolides |
US3442871A (en) * | 1966-05-04 | 1969-05-06 | American Cyanamid Co | Process for polymerizing a glycolide |
US3468853A (en) * | 1966-06-15 | 1969-09-23 | American Cyanamid Co | Process of polymerizing a glycolide |
US3457280A (en) * | 1967-06-12 | 1969-07-22 | American Cyanamid Co | Alpha-glycolide and methods for the isolation thereof |
US3435008A (en) * | 1967-08-22 | 1969-03-25 | American Cyanamid Co | Method for preparation of isomerically pure beta-glycolide and polymerization method for glycolide compositions employing partial hydrolyzate of said beta-glycolide |
US3636956A (en) * | 1970-05-13 | 1972-01-25 | Ethicon Inc | Polylactide sutures |
US3797499A (en) * | 1970-05-13 | 1974-03-19 | Ethicon Inc | Polylactide fabric graphs for surgical implantation |
US3846382A (en) * | 1971-02-25 | 1974-11-05 | American Cyanamid Co | Sterile medical dusting powder |
US3982543A (en) * | 1973-04-24 | 1976-09-28 | American Cyanamid Company | Reducing capillarity of polyglycolic acid sutures |
US4048256A (en) * | 1976-06-01 | 1977-09-13 | American Cyanamid Company | Normally-solid, bioabsorbable, hydrolyzable, polymeric reaction product |
US4095600A (en) * | 1976-06-01 | 1978-06-20 | American Cyanamid Company | Normally-solid, bioabsorbable, hydrolyzable, polymeric reaction product |
US4377010A (en) * | 1978-11-08 | 1983-03-22 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Biocompatible material comprising a base polymer bulk graft polymerized with an ethylenically unsaturated carboxylic acid |
US4243775A (en) * | 1978-11-13 | 1981-01-06 | American Cyanamid Company | Synthetic polyester surgical articles |
US4523591A (en) * | 1982-10-22 | 1985-06-18 | Kaplan Donald S | Polymers for injection molding of absorbable surgical devices |
US4443430A (en) * | 1982-11-16 | 1984-04-17 | Ethicon, Inc. | Synthetic absorbable hemostatic agent |
US4906474A (en) * | 1983-03-22 | 1990-03-06 | Massachusetts Institute Of Technology | Bioerodible polyanhydrides for controlled drug delivery |
US4946929A (en) * | 1983-03-22 | 1990-08-07 | Massachusetts Institute Of Technology | Bioerodible articles useful as implants and prostheses having predictable degradation rates |
US4594407A (en) * | 1983-09-20 | 1986-06-10 | Allied Corporation | Prosthetic devices derived from krebs-cycle dicarboxylic acids and diols |
DE3433331A1 (en) * | 1983-09-20 | 1985-03-28 | Materials Consultants Oy, Tampere | SURGICAL DEVICE FOR IMMOBILIZING BONE FRACTURES |
US5124103A (en) * | 1984-03-06 | 1992-06-23 | United States Surgical Corporation | Two phase compositions for absorbable surgical devices |
US4886870A (en) * | 1984-05-21 | 1989-12-12 | Massachusetts Institute Of Technology | Bioerodible articles useful as implants and prostheses having predictable degradation rates |
US4891225A (en) * | 1984-05-21 | 1990-01-02 | Massachusetts Institute Of Technology | Bioerodible polyanhydrides for controlled drug delivery |
US4727163A (en) * | 1985-07-11 | 1988-02-23 | E. I. Du Pont De Nemours And Company | Process for preparing highly pure cyclic esters |
US5061281A (en) * | 1985-12-17 | 1991-10-29 | Allied-Signal Inc. | Bioresorbable polymers and implantation devices thereof |
US5399353A (en) * | 1986-06-20 | 1995-03-21 | Henkel Kommanditgesellschaft Auf Aktien | Preparations for covering undamaged and/or damaged areas of human or animal skin |
US4744365A (en) * | 1986-07-17 | 1988-05-17 | United States Surgical Corporation | Two-phase compositions for absorbable surgical devices |
EP0385000A1 (en) * | 1987-02-24 | 1990-09-05 | E.I. Du Pont De Nemours And Company | Atmospheric pressure process for preparing cyclic esters |
US4835293A (en) * | 1987-02-24 | 1989-05-30 | E. I. Du Pont De Nemours And Company | Atmospheric pressure process for preparing pure cyclic esters |
US6323307B1 (en) | 1988-08-08 | 2001-11-27 | Cargill Dow Polymers, Llc | Degradation control of environmentally degradable disposable materials |
US5545409A (en) * | 1989-02-22 | 1996-08-13 | Massachusetts Institute Of Technology | Delivery system for controlled release of bioactive factors |
EP0450777A2 (en) * | 1990-04-06 | 1991-10-09 | Director-General Of The Agency Of Industrial Science And Technology | Biodegradable plastics composition |
EP0450777A3 (en) * | 1990-04-06 | 1992-05-20 | Director-General Of The Agency Of Industrial Science And Technology | Biodegradable plastic composition |
US5091544A (en) * | 1990-05-08 | 1992-02-25 | E. I. Du Pont De Nemours And Company | Process for rapid conversion of oligomers to cyclic esters |
WO1992000292A1 (en) * | 1990-06-28 | 1992-01-09 | E.I. Du Pont De Nemours And Company | Continuous catalyzed vapor phase dimeric cyclic ester process |
US5138074A (en) * | 1990-06-28 | 1992-08-11 | E. I. Du Pont De Nemours And Company | Continuous catalyzed vapor phase dimeric cyclic ester process |
WO1992000974A1 (en) * | 1990-07-13 | 1992-01-23 | E.I. Du Pont De Nemours And Company | High yield recycle process for lactide |
US5136057A (en) * | 1990-07-13 | 1992-08-04 | E. I. Du Pont De Nemours And Company | High yield recycle process for lactide |
US5076983A (en) * | 1990-07-16 | 1991-12-31 | E. I. Du Pont De Nemours And Company | Polyhydroxy acid films |
US5319107A (en) * | 1990-09-18 | 1994-06-07 | Biopak Technology, Ltd. | Method to produce cyclic esters |
US5274127A (en) * | 1990-09-18 | 1993-12-28 | Biopak Technology, Ltd. | Lactide production from dehydration of aqueous lactic acid feed |
US5332839A (en) * | 1990-09-18 | 1994-07-26 | Biopak Technology, Ltd. | Catalytic production of lactide directly from lactic acid |
US5266706A (en) * | 1990-10-23 | 1993-11-30 | E. I. Du Pont De Nemours & Company | Solvent scrubbing recovery of lactide and other dimeric cyclic esters |
WO1992006969A1 (en) * | 1990-10-23 | 1992-04-30 | E.I. Du Pont De Nemours And Company | Solvent scrubbing recovery of cyclic esters |
US5117008A (en) * | 1990-10-23 | 1992-05-26 | E. I. Du Pont De Nemours And Company | Solvent scrubbing recovery of lactide and other dimeric cyclic esters |
US5089632A (en) * | 1991-01-30 | 1992-02-18 | E. I. Du Pont De Nemours And Company | Process for preparing cyclic esters using a fluorocarbon |
US6228954B1 (en) | 1991-02-12 | 2001-05-08 | United States Surgical Corporation | Blends of glycolide and/or lactide polymers and caprolactone and/or trimethylene carbonate polymers and absorabable surgical devices made therefrom |
US5475063A (en) * | 1991-02-12 | 1995-12-12 | United States Surgical Corporation | Blends of glycolide and/or lactide polymers and caprolactone and/or trimethylene carbonate polymers and absorbable surgical devices made |
US5288881A (en) * | 1992-03-12 | 1994-02-22 | E. I. Du Pont De Nemours And Company | Continuous reduced pressure dimeric cyclic ester production |
US5236560A (en) * | 1992-03-13 | 1993-08-17 | E. I. Du Pont De Nemours And Company | Solventless dimeric cyclic ester distillation process |
US5750732A (en) * | 1992-03-19 | 1998-05-12 | Chronopol, Inc. | Method to produce cyclic esters |
US5420304A (en) * | 1992-03-19 | 1995-05-30 | Biopak Technology, Ltd. | Method to produce cyclic esters |
US5675021A (en) * | 1992-03-19 | 1997-10-07 | Chronopol, Inc. | Method to produce and purify cyclic esters |
US5856523A (en) * | 1992-03-19 | 1999-01-05 | Chronopol, Inc. | Purifying cyclic esters by aqueous solvent extraction and further purification |
US5399665A (en) * | 1992-11-05 | 1995-03-21 | Massachusetts Institute Of Technology | Biodegradable polymers for cell transplantation |
US6387363B1 (en) | 1992-12-31 | 2002-05-14 | United States Surgical Corporation | Biocompatible medical devices |
US6310218B1 (en) | 1993-02-17 | 2001-10-30 | E.I. Du Pont De Nemours And Company | Melt crystallization purification of lactides |
US5342969A (en) * | 1993-03-03 | 1994-08-30 | E. I. Du Pont De Nemours And Company | Recovery of hydroxycarboxylic acid values from poly(hydroxycarboxylic acids) |
EP0617029A1 (en) | 1993-03-25 | 1994-09-28 | United States Surgical Corporation | Purification of 1,4-dioxan-2-one by crystallization |
US5403347A (en) * | 1993-05-27 | 1995-04-04 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US5522841A (en) * | 1993-05-27 | 1996-06-04 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US5554170A (en) * | 1993-05-27 | 1996-09-10 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US5686630A (en) * | 1993-09-29 | 1997-11-11 | Chronopol, Inc. | Purifying cyclic esters by aqueous solvent extraction |
US5639466A (en) * | 1994-02-24 | 1997-06-17 | Chronopol, Inc. | Method for packaging foodstuffs |
US5431679A (en) * | 1994-03-10 | 1995-07-11 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US7097907B2 (en) | 1994-07-22 | 2006-08-29 | United States Surgical Corporation | Bioabsorbable branched polymers containing units derived from dioxanone and medical/surgical devices manufactured therefrom |
US20060014023A9 (en) * | 1994-07-22 | 2006-01-19 | Bennett Steven L | Bioabsorbable branched polymers containing units derived from dioxanone and medical/surgical devices manufactured therefrom |
US7321008B2 (en) | 1994-07-22 | 2008-01-22 | United States Surgical Corporation | Bioabsorbable branched polymers end-capped with diketene acetals |
EP2301597A1 (en) | 1994-07-22 | 2011-03-30 | United States Surgical Corporation | Bioabsorbable branched polymers containing units derived from dioxanone and medical/surgical devices manufactured therefrom |
EP2036582A1 (en) | 1994-07-22 | 2009-03-18 | United States Surgical Corporation | Biobsorbable branched polymers containing units derived from dioxanone and medical/surgical devices manufactured therefrom |
US20040058164A1 (en) * | 1994-07-22 | 2004-03-25 | Bennett Steven L. | Bioabsorbable branched polymers containing units derived from dioxanone and medical/surgical devices manufactured therefrom |
US20060293406A1 (en) * | 1994-07-22 | 2006-12-28 | Bennett Steven L | Bioabsorbable branched polymers containing units derived from dioxanone and medical/surgical devices manufactured therefrom |
EP0701823A2 (en) | 1994-09-16 | 1996-03-20 | United States Surgical Corporation | Absorbable polymer and surgical articles fabricated therefrom |
US6206908B1 (en) | 1994-09-16 | 2001-03-27 | United States Surgical Corporation | Absorbable polymer and surgical articles fabricated therefrom |
US5618313A (en) * | 1994-10-11 | 1997-04-08 | United States Surgical Corporation | Absorbable polymer and surgical articles fabricated therefrom |
US5997568A (en) * | 1996-01-19 | 1999-12-07 | United States Surgical Corporation | Absorbable polymer blends and surgical articles fabricated therefrom |
US5830991A (en) * | 1996-02-09 | 1998-11-03 | Kureha Kagaku Kagyo Kk | Preparation process and purification process of dimeric cyclic ester of hydroxycarboxylic acid |
US5853639A (en) * | 1996-04-30 | 1998-12-29 | Kureha Kagaku Kogyo K.K. | Oriented polyglycolic acid film and production process thereof |
US5908917A (en) * | 1996-04-30 | 1999-06-01 | Kureha Kagaku Kogyo K.K. | Polyglycolic acid sheet and production process thereof |
EP0805176A1 (en) * | 1996-04-30 | 1997-11-05 | Kureha Kagaku Kogyo Kabushiki Kaisha | Polyglycolic acid sheet and production process thereof |
EP0805175A1 (en) * | 1996-04-30 | 1997-11-05 | Kureha Kagaku Kogyo Kabushiki Kaisha | Oriented polyglycolic acid film and production process thereof |
US5756651A (en) * | 1996-07-17 | 1998-05-26 | Chronopol, Inc. | Impact modified polylactide |
US5908918A (en) * | 1996-07-17 | 1999-06-01 | Chronopol, Inc. | Impact modified polylactide |
US6177095B1 (en) | 1996-09-23 | 2001-01-23 | Focal, Inc | Polymerizable biodegradable polymers including carbonate or dioxanone linkages |
USRE39713E1 (en) | 1996-09-23 | 2007-07-03 | Genzyme Corporation | Polymerizable biodegradable polymers including carbonate or dioxanone linkages |
US6083524A (en) * | 1996-09-23 | 2000-07-04 | Focal, Inc. | Polymerizable biodegradable polymers including carbonate or dioxanone linkages |
US5900491A (en) * | 1996-10-04 | 1999-05-04 | Mitsubishi Gas Chemical Co., Inc. | Preparation process and purification process of cyclic ester |
US6191236B1 (en) | 1996-10-11 | 2001-02-20 | United States Surgical Corporation | Bioabsorbable suture and method of its manufacture |
US20100093796A1 (en) * | 1996-11-12 | 2010-04-15 | Gupta Suneel K | Methods and devices for providing prolonged drug therapy |
US9144549B2 (en) | 1996-11-12 | 2015-09-29 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US20010012847A1 (en) * | 1996-11-12 | 2001-08-09 | Lam Andrew C. | Methods and devices for providing prolonged drug therapy |
US20050238709A1 (en) * | 1996-11-12 | 2005-10-27 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US6930129B2 (en) | 1996-11-12 | 2005-08-16 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US9029416B2 (en) | 1996-11-12 | 2015-05-12 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US9000038B2 (en) | 1996-11-12 | 2015-04-07 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US6919373B1 (en) | 1996-11-12 | 2005-07-19 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US8629179B2 (en) | 1996-11-12 | 2014-01-14 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US8163798B2 (en) | 1996-11-12 | 2012-04-24 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US20050025831A1 (en) * | 1996-11-12 | 2005-02-03 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US20050025832A1 (en) * | 1996-11-12 | 2005-02-03 | Alza Corporation | Methods and devices for providing prolonged drug therapy |
US6007565A (en) * | 1997-09-05 | 1999-12-28 | United States Surgical | Absorbable block copolymers and surgical articles fabricated therefrom |
US6136018A (en) * | 1997-09-05 | 2000-10-24 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US6277927B1 (en) | 1997-11-26 | 2001-08-21 | United States Surgical Corporation | Absorbable block copolymers and surgical articles fabricated therefrom |
US6546188B1 (en) | 1998-01-16 | 2003-04-08 | Sony Corporation | Editing system and editing method |
EP1133240A4 (en) * | 1998-10-02 | 2003-07-30 | Wrigley W M Jun Co | Biodegradable chewing gum bases including plasticized poly(d,l-lactic acid) and copolymers thereof |
EP1133240A1 (en) * | 1998-10-02 | 2001-09-19 | Wm. Wrigley Jr. Company | Biodegradable chewing gum bases including plasticized poly(d,l-lactic acid) and copolymers thereof |
WO2000064538A1 (en) | 1999-04-28 | 2000-11-02 | Medi Physics, Inc. | Products and methods for brachytherapy |
US6916939B2 (en) | 2000-08-11 | 2005-07-12 | Kureha Kagaku Kogyo K.K. | Process for the preparation of cyclic esters and method for purification of the same |
US20030191326A1 (en) * | 2000-08-11 | 2003-10-09 | Kazuyuki Yamane | Process for the preparation of cyclic esters and method for purification of the same |
US6716932B2 (en) | 2000-08-16 | 2004-04-06 | Tyco Healthcare Group Lp | High consistency absorbable polymeric resin |
US20040162580A1 (en) * | 2000-08-17 | 2004-08-19 | Matthew Hain | Sutures and coatings made from therapeutic absorbable glass |
US6881766B2 (en) | 2000-08-17 | 2005-04-19 | Tyco Healthcare Group Lp | Sutures and coatings made from therapeutic absorbable glass |
US20090253950A1 (en) * | 2000-11-01 | 2009-10-08 | Michael Rapach | Radioactive member and method of making |
US7547274B2 (en) | 2000-11-01 | 2009-06-16 | Medi-Physics, Inc. | Radioactive member and method of making |
US8033981B2 (en) | 2000-11-01 | 2011-10-11 | Medi-Physics, Inc. | Radioactive member and method of making |
US20040015037A1 (en) * | 2000-11-01 | 2004-01-22 | Michael Rapach | Radioactive member and method of making |
US6905455B2 (en) | 2000-11-01 | 2005-06-14 | Medi-Physics, Inc. | Radioactive member and method of making |
US20060058570A1 (en) * | 2000-11-01 | 2006-03-16 | Michael Rapach | Radioactive member and method of making |
US20100261946A1 (en) * | 2000-11-16 | 2010-10-14 | Microspherix Llc | Flexible and/or elastic brachytherapy seed or strand |
US10994058B2 (en) | 2000-11-16 | 2021-05-04 | Microspherix Llc | Method for administering a flexible hormone rod |
US10493181B2 (en) | 2000-11-16 | 2019-12-03 | Microspherix Llc | Flexible and/or elastic brachytherapy seed or strand |
US9636402B2 (en) | 2000-11-16 | 2017-05-02 | Microspherix Llc | Flexible and/or elastic brachytherapy seed or strand |
US8470294B2 (en) | 2000-11-16 | 2013-06-25 | Microspherix Llc | Flexible and/or elastic brachytherapy seed or strand |
US9636401B2 (en) | 2000-11-16 | 2017-05-02 | Microspherix Llc | Flexible and/or elastic brachytherapy seed or strand |
US8821835B2 (en) | 2000-11-16 | 2014-09-02 | Microspherix Llc | Flexible and/or elastic brachytherapy seed or strand |
US20040087805A1 (en) * | 2001-03-06 | 2004-05-06 | Kazuyuki Yamane | Glycolide production process, and glycolic acid composition |
US6891048B2 (en) | 2001-03-06 | 2005-05-10 | Kureha Kagaku Kogyo Kk | Glycolide production process, and glycolic acid composition |
US7235673B2 (en) | 2001-04-12 | 2007-06-26 | Kureha Corporation | Glycolide production process, and glycolic acid oligomer for glycolide production |
US20040122240A1 (en) * | 2001-04-12 | 2004-06-24 | Kazuyuki Yamane | Glycolide production process, and glycolic acid oligomer for glycolide production |
WO2003006525A1 (en) * | 2001-07-10 | 2003-01-23 | Kureha Chemical Industry Company, Limited | Polyhydroxycarboxylic acid and its production process |
US20040230026A1 (en) * | 2001-07-10 | 2004-11-18 | Kazuyuki Yamane | Polyester production process and reactor apparatus |
US6852827B2 (en) | 2001-07-10 | 2005-02-08 | Kureha Chemical Industry Company, Limited | Polyester production process and reactor apparatus |
CN100413906C (en) * | 2001-07-10 | 2008-08-27 | 株式会社吴羽 | Polyhydroxycarboxylic acid and its production process |
US7067611B2 (en) | 2001-07-10 | 2006-06-27 | Kureha Corporation | Polyhydroxycarboxylic acid and its production process |
US20040192881A1 (en) * | 2001-07-10 | 2004-09-30 | Kazuyuki Yamane | Polyhydroxycarboxylic acid and its production process |
EP1449864A1 (en) * | 2001-10-31 | 2004-08-25 | Kureha Chemical Industry Co., Ltd. | CRYSTALLINE POLYGLYCOLIC ACID, POLYGLYCOLIC ACID COMPOSITION AND PROCESSES FOR PRODUCTION OF BOTH |
EP1449864A4 (en) * | 2001-10-31 | 2005-04-20 | Kureha Chemical Ind Co Ltd | Crystalline polyglycolic acid, polyglycolic acid composition and processes for production of both |
EP1914258A1 (en) * | 2001-10-31 | 2008-04-23 | Kureha Corporation | Crystalline polyglycolic acid, polyglycolic acid composition and production process thereof |
US6951956B2 (en) | 2001-10-31 | 2005-10-04 | Kureha Kagaku Kogyo K.K. | Crystalline polyglycolic acid, polyglycolic acid composition and production process thereof |
AU2002343784C1 (en) * | 2001-10-31 | 2008-09-11 | Kureha Corporation | Crystalline polyglycolic acid, polyglycolic acid composition and production process thereof |
AU2002343784B2 (en) * | 2001-10-31 | 2008-01-31 | Kureha Corporation | Crystalline polyglycolic acid, polyglycolic acid composition and production process thereof |
US8066627B2 (en) | 2001-11-02 | 2011-11-29 | Biocompatibles Uk Limited | Delivery system and method for interstitial radiation therapy using strands constructed with extruded strand housings |
US20060235365A1 (en) * | 2001-11-02 | 2006-10-19 | World Wide Medical Technologies, Llc | Delivery system and method for interstitial radiation therapy using strands constructed with extruded strand housings |
US7874974B2 (en) | 2001-11-02 | 2011-01-25 | Biocompatibles Uk Limited | Delivery system and method for interstitial radiation therapy |
US20050208132A1 (en) * | 2002-07-29 | 2005-09-22 | Gayatri Sathyan | Methods and dosage forms for reducing side effects of benzisozazole derivatives |
US20090202631A1 (en) * | 2002-07-29 | 2009-08-13 | Yam Nyomi V | Methods and dosage forms for controlled delivery of paliperidone and risperidone |
US9393192B2 (en) | 2002-07-29 | 2016-07-19 | Alza Corporation | Methods and dosage forms for controlled delivery of paliperidone and risperidone |
US20050232995A1 (en) * | 2002-07-29 | 2005-10-20 | Yam Nyomi V | Methods and dosage forms for controlled delivery of paliperidone and risperidone |
US20060004183A1 (en) * | 2002-10-08 | 2006-01-05 | Hiroyuki Sato | Process for producing aliphatic polyester |
US7622546B2 (en) | 2002-10-08 | 2009-11-24 | Kureha Corporation | Production process of aliphatic polyester |
US8007427B2 (en) | 2003-03-17 | 2011-08-30 | Medi-Physics, Inc. | Products and methods for brachytherapy |
US7322928B2 (en) | 2003-03-17 | 2008-01-29 | Medi-Physics, Inc. | Products and methods for brachytherapy |
EP2221333A1 (en) | 2004-03-18 | 2010-08-25 | Kureha Corporation | Process for producing aliphatic polyester reduced in residual cyclic ester content |
US20090149692A1 (en) * | 2005-07-22 | 2009-06-11 | Biocompatibles Uk Limited | Implants for use in brachytherapy and other radiation therapy that resist migration and rotation |
US8790235B2 (en) | 2005-07-22 | 2014-07-29 | Eckert & Ziegler Debig S.A. | Devices to resist migration and rotation of implants used in brachytherapy and other radiation therapy |
US7972261B2 (en) | 2005-07-22 | 2011-07-05 | Biocompatibles Uk Limited | Devices to resist migration and rotation of implants used in brachytherapy and other radiation therapy |
US20090099402A1 (en) * | 2005-07-22 | 2009-04-16 | Biocompatibles Uk Limited | Implants for use in brachytherapy and other radiation therapy that resist migration and rotation |
US8021291B2 (en) | 2005-07-22 | 2011-09-20 | Biocompatibles Uk Limited | Markers for use in brachytherapy and other radiation therapy that resist migration and rotation |
US20070021642A1 (en) * | 2005-07-22 | 2007-01-25 | Worldwide Medical Technologies Llc | Devices to resist migration and rotation of implants used in brachytherapy and other radiation therapy |
US20090312594A1 (en) * | 2005-07-22 | 2009-12-17 | Biocompatibles Uk Limited | Devices to resist migration and rotation of implants used in brachytherapy and other radiation therapy |
US8795146B2 (en) | 2005-07-22 | 2014-08-05 | Eckert & Ziegler Bebig S.A. | Implants including spacers for use in brachytherapy and other radiation therapy that resist migration and rotation |
US20090124846A1 (en) * | 2005-07-22 | 2009-05-14 | Biocompatibles Uk Limited | Anchor seed cartridge for use with brachytherapy applicator |
US8114007B2 (en) | 2005-07-22 | 2012-02-14 | Biocompatibles Uk Limited | Implants for use in brachytherapy and other radiation therapy that resist migration and rotation |
US20090124894A1 (en) * | 2005-07-22 | 2009-05-14 | Biocompatibles Uk Limited | Markers for use in brachytherapy and other radiation therapy that resist migration and rotation |
US8187159B2 (en) | 2005-07-22 | 2012-05-29 | Biocompatibles, UK | Therapeutic member including a rail used in brachytherapy and other radiation therapy |
US8192345B2 (en) | 2005-07-22 | 2012-06-05 | Biocompatibles, UK | Cartridge for use with brachytherapy applicator |
WO2007086563A1 (en) | 2006-01-30 | 2007-08-02 | Kureha Corporation | Process for producing aliphatic polyester |
US20070265488A1 (en) * | 2006-05-09 | 2007-11-15 | Worldwide Medical Technologies Llc | After-loader for positioning implants for needle delivery in brachytherapy and other radiation therapy |
US7988611B2 (en) | 2006-05-09 | 2011-08-02 | Biocompatibles Uk Limited | After-loader for positioning implants for needle delivery in brachytherapy and other radiation therapy |
US7985172B2 (en) | 2006-05-09 | 2011-07-26 | Biocompatibles Uk Limited | After-loader devices and kits |
US7874976B1 (en) | 2006-09-07 | 2011-01-25 | Biocompatibles Uk Limited | Echogenic strands and spacers therein |
US7878964B1 (en) | 2006-09-07 | 2011-02-01 | Biocompatibles Uk Limited | Echogenic spacers and strands |
US20100080839A1 (en) * | 2007-03-01 | 2010-04-01 | Bioneedle Technologies Group B.V. | Parenteral formulation |
US8486439B2 (en) | 2007-03-01 | 2013-07-16 | Bioneedle Technologies Group B.V. | Parenteral formulation |
US20100015185A1 (en) * | 2007-03-01 | 2010-01-21 | Bioneedle Technologies Group B.V. | Biodegradable material based on opened starch |
US8383134B2 (en) | 2007-03-01 | 2013-02-26 | Bioneedle Technologies Group B.V. | Biodegradable material based on opened starch |
US20090216063A1 (en) * | 2008-01-29 | 2009-08-27 | Biocompatibles Uk Limited | Bio-absorbable brachytherapy strands |
US8729156B2 (en) | 2009-07-17 | 2014-05-20 | Arkema France | Polyhydroxyalkanoate composition exhibiting improved impact resistance at low levels of impact modifier |
WO2011007092A1 (en) | 2009-07-17 | 2011-01-20 | Arkema France | Polyhydroalkanoate composition exhibiting improved impact resistance |
US8642703B2 (en) | 2009-07-17 | 2014-02-04 | Arkema France | Polyhydroalkanoate composition exhibiting improved impact resistance |
WO2011017153A1 (en) | 2009-07-28 | 2011-02-10 | E. I. Du Pont De Nemours And Company | Poly(hydroxyalkanoic acid) blown film |
US8399686B2 (en) | 2009-12-21 | 2013-03-19 | Evonik Degussa Corporation | Process for preparing cyclic esters comprising unsaturated functional groups and polyesters prepared from same |
US8758828B2 (en) | 2009-12-21 | 2014-06-24 | Evonik Corporation | Process for preparing cyclic esters comprising unsaturated functional groups and polyesters prepared from same |
EP2407463A1 (en) | 2010-07-14 | 2012-01-18 | Solvay SA | Process for the manufacture of a cyclic diester of an apha-hydroxyacid |
US8981124B2 (en) | 2010-07-14 | 2015-03-17 | Solvay Sa | Process for the manufacture of a cyclic diester of an alpha-hydroxyacid |
WO2012007379A1 (en) | 2010-07-14 | 2012-01-19 | Solvay Sa | Process for the manufacture of a cyclic diester of an alpha-hydroxyacid |
WO2013063310A1 (en) | 2011-10-26 | 2013-05-02 | E. I. Du Pont De Nemours And Company | Multilayer film structure comprising renewably sourced materials |
EP2732832A2 (en) | 2012-11-14 | 2014-05-21 | Universitair Medisch Centrum Groningen (UMCG) | Drug delivery device comprising an active compound and a thermo-sensitive polymeric material |
US9365536B2 (en) | 2012-11-22 | 2016-06-14 | Kureha Corporation | Method for producing glycolide, which is provided with rectification step by means of gas-liquid countercurrent contact, and method for purifying crude glycolide |
WO2014080876A1 (en) | 2012-11-22 | 2014-05-30 | 株式会社クレハ | Method for producing glycolide, which is provided with rectification step by means of gas-liquid countercurrent contact, and method for purifying crude glycolide |
US9643949B2 (en) | 2013-03-27 | 2017-05-09 | Kureha Corporation | Method for producing glycolide |
WO2014156809A1 (en) | 2013-03-27 | 2014-10-02 | 株式会社クレハ | Method for producing glycolide |
US9080013B2 (en) | 2013-07-22 | 2015-07-14 | Kureha Corporation | Production method for aliphatic polyester |
US11046665B2 (en) | 2017-01-24 | 2021-06-29 | Kureha Corporation | Method for producing α-hydroxycarboxylic acid dimeric cyclic ester |
US10759097B2 (en) | 2017-01-27 | 2020-09-01 | Kureha Corporation | Molded article and use of same |
CN116284698A (en) * | 2023-02-21 | 2023-06-23 | 内蒙古久泰新材料科技股份有限公司 | Production process for simultaneously preparing various molecular weight gradient degradable materials |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2668162A (en) | Preparation of high molecular weight polyhydroxyacetic ester | |
US2676945A (en) | Condensation polymers of hydroxyacetic acid | |
JP2017527667A (en) | Solution polymer, solution polymerization method and polymer composition comprising one or more 1,1-disubstituted alkene compounds | |
US2172374A (en) | Polymerization process | |
JPH0327585B2 (en) | ||
US3021316A (en) | Polymerization of cyclic esters | |
US3265640A (en) | Crosslinked polymers from alpha, alpha-dichloro-p-xylene and polysubstituted benzenes | |
Thomas et al. | The anionic polymerization of some alkyl vinyl ketones | |
US3651015A (en) | Process for producing polyacetal resin | |
US2585427A (en) | Process fob preparing condensation | |
US3753957A (en) | Process for preparing aromatic polyamides by condensation of an aromatic ester of an aromatic amino acid | |
JP4078452B2 (en) | High refractive index monomer | |
US2891038A (en) | Polymerization procedures | |
US3901854A (en) | Two stage process for preparing aromatic polyamides | |
US2719835A (en) | Nitrogen-containing linear polyesters | |
US3342785A (en) | 3-hydroxy-3-methylcyclobutanecarboxylic acids, lactones thereof and their polymers | |
US3531435A (en) | Film-forming aromatic polyketoester polymers and percursors | |
US3567696A (en) | Storable polyamide-forming compositions and process for the production of polyamides | |
US2844545A (en) | Method for the polymerization of olefin oxides with ferric compounds | |
US3256245A (en) | Production of high molecular weight polyoxymethylenes | |
Dumas et al. | Temperature effect on the stereoelective polymerization of methylthiirane in homogeneous phase | |
US3679637A (en) | Cationic precipitation polymerization of vinyl carbazole | |
US2853474A (en) | New lactone | |
US2628216A (en) | Process for preparing polyamides from dinitriles and disecondary alcohols or their esters | |
US2701246A (en) | Method of preparing a cyclic carbamate |